Evidence increasingly supports the role of palliative care in improving both the efficiency of care and the quality of life of patients and caregivers living with advanced chronic serious illness. Improving access to and use of palliative care is becoming more important with our aging population and prevalence of advanced chronic illness, as well as fiscal constraints on healthcare spending. RAND Health developed the Future Elderly Model (FEM) for the Center for Medicare and Medicaid Services (CMS) to evaluate the impact of healthcare innovations on the utilization and cost of care, as well as patient and caregiver outcomes. RAND has used FEM to evaluate the future impact of changing demographics, lifestyle choices, novel technologies, and other trends for CMS. We propose to evaluate trajectories of serious chronic illness using data from the Medicare Current Beneficiary Survey (MCBS) and the Health and Retirement Survey (HRS) to characterize function, pain, emotional wellbeing over time among patients and their caregivers, comparing both prospective and retrospective approaches, and narrow and broad categorizations of cancer, organ failure, and frailty trajectories. We will evaluate a range of patient characteristics and healthcare events tha are associated with critical changes in those trajectories, in order to characterize possible triggers for implementing palliative care. We will update and expand extensive literature reviews we previously conducted for the NIH State of the Science Meeting on End of Life Care in 2004 in order to synthesize the literature on the effectiveness of palliative services including hospice in improving QOL, utilization, and cost outcomes. Informed by the literature, an expert panel will then rate the feasibility and validity of policy scenarios to implement palliative care hat address the timing, setting, and composition of palliative care services. Finally, informed by our empiric examination of trajectories, a synthesis of the literature, and ratings of the panel, we wil use the FEM to consider the impact of the highest priority policy scenarios to implement palliative care services on patients, caregivers, and Medicare utilization and cost. Our team has worked closely together conducting research on policy-relevant aspects of palliative and end of life care, and members of our team have extensive policy experience developing, implementing, and evaluating policies to improve the care of advanced serious chronic illness. We have tremendous expertise in the methods of the proposed project including quantitative analyses, literature syntheses, appropriateness panel methodologies, and policy dissemination. This project will not only inform policy, but also identify critical gaps in the understanding of trajectories and the effectiveness of palliative care to inform research priorities.